# Copyright 2015 The TensorFlow Authors. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# ==============================================================================
"""
Top-level module of TensorFlow. By convention, we refer to this module as
`tf` instead of `tensorflow`, following the common practice of importing
TensorFlow via the command `import tensorflow as tf`.

The primary function of this module is to import all of the public TensorFlow
interfaces into a single place. The interfaces themselves are located in
sub-modules, as described below.

Note that the file `__init__.py` in the TensorFlow source code tree is actually
only a placeholder to enable test cases to run. The TensorFlow build replaces
this file with a file generated from [`api_template.__init__.py`](https://www.github.com/tensorflow/tensorflow/blob/master/tensorflow/api_template.__init__.py)
"""

import distutils as _distutils
import inspect as _inspect
import logging as _logging
import os as _os
import site as _site
import sys as _sys
import typing as _typing

from tensorflow.python.tools import module_util as _module_util
from tensorflow.python.util.lazy_loader import LazyLoader as _LazyLoader

# Make sure code inside the TensorFlow codebase can use tf2.enabled() at import.
_os.environ['TF2_BEHAVIOR'] = '1'
from tensorflow.python import tf2 as _tf2
_tf2.enable()

# API IMPORTS PLACEHOLDER

# WRAPPER_PLACEHOLDER

# Make sure directory containing top level submodules is in
# the __path__ so that "from tensorflow.foo import bar" works.
# We're using bitwise, but there's nothing special about that.
_API_MODULE = _sys.modules[__name__].bitwise
_tf_api_dir = _os.path.dirname(_os.path.dirname(_API_MODULE.__file__))
_current_module = _sys.modules[__name__]

if not hasattr(_current_module, '__path__'):
  __path__ = [_tf_api_dir]
elif _tf_api_dir not in __path__:
  __path__.append(_tf_api_dir)

# Hook external TensorFlow modules.
# Import compat before trying to import summary from tensorboard, so that
# reexport_tf_summary can get compat from sys.modules. Only needed if using
# lazy loading.
_current_module.compat.v2  # pylint: disable=pointless-statement
try:
  from tensorboard.summary._tf import summary
  _current_module.__path__ = (
      [_module_util.get_parent_dir(summary)] + _current_module.__path__)
  setattr(_current_module, "summary", summary)
except ImportError:
  _logging.warning(
      "Limited tf.summary API due to missing TensorBoard installation.")

# Load tensorflow-io-gcs-filesystem if enabled
# pylint: disable=g-import-not-at-top
if (_os.getenv('TF_USE_MODULAR_FILESYSTEM', '0') == 'true' or
    _os.getenv('TF_USE_MODULAR_FILESYSTEM', '0') == '1'):
  import tensorflow_io_gcs_filesystem as _tensorflow_io_gcs_filesystem
# pylint: enable=g-import-not-at-top

# Lazy-load estimator.
_estimator_module = "tensorflow_estimator.python.estimator.api._v2.estimator"
estimator = _LazyLoader("estimator", globals(), _estimator_module)
_module_dir = _module_util.get_parent_dir_for_name(_estimator_module)
if _module_dir:
  _current_module.__path__ = [_module_dir] + _current_module.__path__
setattr(_current_module, "estimator", estimator)

_keras_module = "keras.api._v2.keras"
keras = _LazyLoader("keras", globals(), _keras_module)
_module_dir = _module_util.get_parent_dir_for_name(_keras_module)
if _module_dir:
  _current_module.__path__ = [_module_dir] + _current_module.__path__
setattr(_current_module, "keras", keras)

# Explicitly import lazy-loaded modules to support autocompletion.
# pylint: disable=g-import-not-at-top
if _typing.TYPE_CHECKING:
  from tensorflow_estimator.python.estimator.api._v2 import estimator
# pylint: enable=g-import-not-at-top

# Enable TF2 behaviors
from tensorflow.python.compat import v2_compat as _compat  # pylint: disable=g-import-not-at-top
_compat.enable_v2_behavior()
_major_api_version = 2


# Load all plugin libraries from site-packages/tensorflow-plugins if we are
# running under pip.
# TODO(gunan): Enable setting an environment variable to define arbitrary plugin
# directories.
# TODO(gunan): Find a better location for this code snippet.
from tensorflow.python.framework import load_library as _ll
from tensorflow.python.lib.io import file_io as _fi

# Get sitepackages directories for the python installation.
_site_packages_dirs = []
if _site.ENABLE_USER_SITE and _site.USER_SITE is not None:
  _site_packages_dirs += [_site.USER_SITE]
_site_packages_dirs += [_p for _p in _sys.path if 'site-packages' in _p]
if 'getsitepackages' in dir(_site):
  _site_packages_dirs += _site.getsitepackages()

if 'sysconfig' in dir(_distutils):
  _site_packages_dirs += [_distutils.sysconfig.get_python_lib()]

_site_packages_dirs = list(set(_site_packages_dirs))

# Find the location of this exact file.
_current_file_location = _inspect.getfile(_inspect.currentframe())

def _running_from_pip_package():
  return any(
      _current_file_location.startswith(dir_) for dir_ in _site_packages_dirs)

if _running_from_pip_package():
  # TODO(gunan): Add sanity checks to loaded modules here.

  # Load first party dynamic kernels.
  _tf_dir = _os.path.dirname(_current_file_location)
  _kernel_dir = _os.path.join(_tf_dir, 'core', 'kernels')
  if _os.path.exists(_kernel_dir):
    _ll.load_library(_kernel_dir)

  # Load third party dynamic kernels.
  for _s in _site_packages_dirs:
    _plugin_dir = _os.path.join(_s, 'tensorflow-plugins')
    if _os.path.exists(_plugin_dir):
      _ll.load_library(_plugin_dir)
      # Load Pluggable Device Library
      _ll.load_pluggable_device_library(_plugin_dir)

# Add module aliases
if hasattr(_current_module, 'keras'):
  # It is possible that keras is a lazily loaded module, which might break when
  # actually trying to import it. Have a Try-Catch to make sure it doesn't break
  # when it doing some very initial loading, like tf.compat.v2, etc.
  try:
    _keras_package = "keras.api._v2.keras."
    losses = _LazyLoader("losses", globals(), _keras_package + "losses")
    metrics = _LazyLoader("metrics", globals(), _keras_package + "metrics")
    optimizers = _LazyLoader(
        "optimizers", globals(), _keras_package + "optimizers")
    initializers = _LazyLoader(
        "initializers", globals(), _keras_package + "initializers")
    setattr(_current_module, "losses", losses)
    setattr(_current_module, "metrics", metrics)
    setattr(_current_module, "optimizers", optimizers)
    setattr(_current_module, "initializers", initializers)
  except ImportError:
    pass

# Do an eager load for Keras' code so that any function/method that needs to
# happen at load time will trigger, eg registration of optimizers in the
# SavedModel registry.
# See b/196254385 for more details.
if hasattr(_current_module, "keras"):
  try:
    keras._load()
  except ImportError:
    pass

# pylint: enable=undefined-variable

# Delete modules that should be hidden from dir().
# Don't fail if these modules are not available.
# For e.g. this file will be originally placed under tensorflow/_api/v1 which
# does not have 'python', 'core' directories. Then, it will be copied
# to tensorflow/ which does have these two directories.
# pylint: disable=undefined-variable
try:
  del python
except NameError:
  pass
try:
  del core
except NameError:
  pass
try:
  del compiler
except NameError:
  pass

# __all__ PLACEHOLDER
